Background: Little is known about the early development of the gastric acid
secretion in human neonates. The purpose of this study was to examine the
early development of gastric H,K-adenosine triphosphatase (ATPase) by analy
zing human gastric biopsy specimens.
Methods: Eighty-eight neonates from week 25 to week 42 of gestation who wer
e treated in a neonatal intensive care unit underwent gastroscopy with biop
sy specimens obtained from the corpus. The expression of gastric H,K-ATPase
protein in the gastric biopsy specimens was assessed by Western blot analy
sis, using an antibody directed against the gastric H,K-ATPase. The amount
of H,K-ATPase expressed was compared with age, gender, clinical factors, di
seases, and the macroscopic and histologic findings at endoscopy.
Results: The expression of human gastric H,K-ATPase increased significantly
with gestational age. There was a significant increase in the expression o
f gastric H,K-ATPase during the first 82 days after birth. Boys had a signi
ficantly higher expression of gastric H,K-ATPase than girls did, when it wa
s adjusted for gestational and postnatal age. Neither the clinical features
nor treatments showed significant correlations with the expression of huma
n gastric H,K-ATPase when controlling for gestational and postnatal age.
Conclusions: This study shows that human gastric H,K-ATPase is expressed fr
om week 25 of gestation, which agrees with earlier findings of gastric pH i
n preterm infants. The amount of enzyme expressed increases with gestationa
l and postnatal age. The authors speculate that the susceptibility to gastr
ic lesions seen in neonates is not related to the amount of H,K-ATPase. How
ever, studies elucidating the ontogeny of gastric mucosal defense mechanism
s are warranted. (C) 2000 Lippincott Williams & Wilkins, Inc.